public class test {
    public static int func(int[] array){
     int ret=0;
        for (int i = 0; i <array.length ; i++) {
            ret^=array[i];
        }
        return ret;
    }
    public static void main(String[] args) {
        int[] array={1,1,5,5,6,4,4,8,8};
        System.out.println(func(array));
    }
}
